ES2802827T3 - Stent graft with fixation elements and delivery system - Google Patents

Abstract

Stent graft (10) for introduction into a blood vessel of a patient, with a hollow cylindrical body (11) with a blood side and a vessel side, the stent graft (10) presenting the following: a first section of endoprosthesis graft (12) with a self-expanding endoprosthesis of rings (14) arranged one behind the other in its longitudinal direction from circulating supports in the form of a meander (15) and with a first prosthetic material (17) attached to the rings (14) and joining these to the vessel side of the hollow cylindrical body (11); characterized in that the first endoprosthesis graft section (12) has in each of its rings (14) in each case two loop-shaped fixation elements (20, 21) placed on a common fixation zone (22), placed on the supports (15) of the rings (14) in such a way that by means of their guide located oppositely around the hollow cylindrical body (11) they can be compressed around it along its entire length.

Description

DESCRIPTION

Stent graft with fixation elements and delivery system

The present invention relates to a stent graft with a hollow cylindrical body with a blood side and a vessel side, the stent graft presenting a first stent graft section with a self-expanding stent from rings arranged one behind the other. others in their longitudinal direction from meander-shaped circulating supports and with a first prosthetic material attached to the rings and joining these to the vessel side of the hollow cylindrical body.

Such stent grafts are well known in the state of the art. These stents, also called endovascular or endoluminal stent grafts or simply endoprostheses, are implanted in blood vessels that, for example, are injured due to diseases or the like, aneurysmically dilated or closed in their lumen, whereby the Vessels are seriously impaired in their function or there is a risk of vascular rupture. In the state of the art, various implantable stent devices are known, which keep blood vessels, for example arteries, open after implantation or limit dilation by the bloodstream. Such stents generally have a hollow cylindrical or tubular body, which is inserted into the vessel and fixed in place to hold the vessel lumen erect.

For example, in the state of the art, stent grafts are known which have a wire frame made of a self-expanding material, for example nitinol, the wire frame may other than be attached to a textile tube or PTFE.

For implantation, the stent or stent graft is radially compressed so that its cross-sectional area is significantly reduced and can be easily inserted into the vessel. Due to the spring effect of the metal frame or metal stent, the stent expands back to its original shape, thereby holding its envelope surface, which becomes stuck inside the blood vessel.

For implantation, the stents are radially folded and then introduced into the blood vessel with the help of advanced endoluminal catheters and positioned in the correct position in the vessel. The correct position of the stent can be controlled in this regard, for example, by means of X-ray markers. In order for the stents to remain in the folded state during positioning, they are generally arranged in a sheath or a sheath-shaped tube, which radially presses or compresses the stent inward. This retractable sheath, as it is called, retracts after positioning the stent in the vessel, whereby the stent is supported axially by a stop / slide element, also known as a pusher. The pusher is in this respect positioned in the system with the endoprosthesis and maintains it in its axial position, while the retractable sheath surrounding the pusher is removed from the endoprosthesis, which can in this respect expand and become stuck in the blood vessel.

When releasing a self-expanding stent or stent graft, the physician often has to exert considerable effort in this regard in grasping the catheter sheath and in the handle to position the implant connected to the pusher. Apart from effort, another critical point is often that the endoprosthesis, once released, can no longer be rotated or moved or displaced in the vessel to position it correctly if necessary, otherwise there is a risk of injury to the vessel.

From DE 103 35 948 B3 a stent is known, the supporting frame of which is wrapped and compressed by a thread. The ends of the wire are guided into the support frame from the outside through a deflection and are engaged therein.

Document WO 2011/063972 A1 discloses an introduction system for inserting a medical implant into the vessel of a patient using at least one tensioning wire with which the diameter of an implant can be changed. Furthermore, document US 2007/0100427 A1 describes a device with an endoluminal prosthesis, which has two thread-like attachment elements, which comprise the prosthesis in the distal and proximal areas, and which can compress the prosthesis by shortening it.

Finally, document US 5,776,186 describes an introduction device for a stent graft system that has two nitinol wire loops that form the framework of the stent graft, and on which, after retraction of the delivery catheter that compresses the stent graft, the stent graft is brought into its expanded form.

From EP 1964532 A2 and EP 1117341 B1 it is known, for example, an introduction system which allows the staged release of a stent / stent graft which is kept compressed by a catheter sheath. Furthermore, so-called pistol-type grips are known in the state of the art, which should allow the physician to release with little effort a stent graft that is also maintained compressed by a catheter sheath.

However, the exposed introduction systems have the disadvantage that with them it is difficult or impossible to position the endoprosthesis in this way before it is definitively released, that is, to rotate or displace it, so that it will be correctly positioned. This is especially critical with stent grafts / stents with side branches, as these must extend into the branching blood vessels after release of the stent / stent graft. US 5873906 shows a stent graft that can be held in a compressed state by means of handles.

In this regard, the object of the present invention is to provide a stent / stent graft and an alternative delivery system with the aid of which the stent / stent graft can be easily compressed and inserted, as well as released in such a way that there is possibility of correctly positioning the stent immediately prior to final release.

The invention is defined by claims 1 and 6. According to the invention, this objective is solved by an improvement of the aforementioned endoprosthesis graft, presenting its first endoprosthesis graft section in each of its rings, in each case two elements of loop-shaped fixations placed on a common fixation zone, which are placed in the ring supports in such a way that through their opposite guide around the hollow cylindrical body, the stent graft can be compressed along its entire length. length.

Furthermore, the objective is solved by an introduction system for a stent graft as described above which, in order to compress and introduce the stent graft into the blood vessel, further has at least one pin element, which is configured to collect from threaded manner and temporarily fix the loop-shaped fasteners that compress the stent graft.

In this way, the object on which the invention is based is fully solved. With the endoprosthesis graft according to the invention or with the delivery system according to the invention it is possible to position the endoprosthesis graft correctly and, if necessary, rotate it after it has been positioned to precisely position the intended lateral branches of the endoprosthesis graft if necessary in branched vessels. A stepwise release of the stent graft is also achieved, the individual release steps of which can be concretely controlled.

With the loop-shaped fasteners attached to the stent graft ring holders, it is possible to compress the stent graft. The two loop-shaped fixation elements, also described by the synonym "handles" consistently throughout the application, are placed on the stent graft according to the invention on their stent rings or on their supports, preferably sewn. The handle-shaped fastening elements are in this case placed on the supports in a common fastening zone, preferably sewn together; This common fastening area can in this case lead on a section of the support or be in the shape of a point. In order to compress the stent graft, one handle of the two loop-shaped fasteners turns in this respect to the right, relative to the perimeter of the stent graft or the hollow cylindrical body, and one handle to the left ; the two handles then "meet" at the place opposite to the point of attachment of the attachment elements on the perimeter of the hollow cylindrical body, where they can be positioned one above the other. In this way, the stent graft can "come together" in the region of the fixation elements and thus compressed.

The handle-shaped fasteners are preferably made of a threadlike material commonly used in medicine; for example, the same material can be used as that used to attach the stent rings to the prosthetic material; it is preferably a synthetic yarn, preferably polyester, polyamide, polytetraflurethylene or ultra-high molecular weight polyethylene (PEUAPM) or mixtures thereof, for example, containing the mentioned materials.

In the endoprosthesis graft according to the invention, it is provided in this connection that the endoprosthesis graft has in each of its rings in each case two loop-shaped fixation elements positioned on a common fixation zone or fixation point.

This feature has the advantage that the stent graft can thus be compressed along its entire length.

The handle-shaped fastening elements can in this case be offset against each other in the circumference of the hollow cylindrical body of the stent graft or be positioned adjacently one behind the other on the supports in the longitudinal direction.

According to another embodiment of the stent graft according to the invention, the first stent graft section may also have at least one lateral branch, preferably at least two or three lateral stent branches, which are configured to be inserted into a vessel branches off the blood vessel.

According to another embodiment, the stent graft has a second stent graft section with a tubular body made of a second prosthetic material; This material can be identical to the first prosthetic material, or it can consist of a different material or present said material; in this regard, the second stent graft section does not have stent rings. Furthermore, according to another embodiment, it may be preferable that this second stent graft section has at least one stent side branch, even more preferable that it has two or three stent side limbs.

The second stent graft section can be provided in particular for the reconstruction of injured or damaged blood vessels and, as a rule, is sewn in such a way in such devices that diseased or injured or damaged areas are no longer, or they are not very functional, they can be replaced by the second stent graft section. For example, and in particular, the second endoprosthesis graft section can be provided for the reconstruction of the aortic arch and the ascending aorta, in particular if this section has three lateral branches, which in each case are intended for the brachiocephalic trunk, the common carotid artery and the left subclavian artery, into whose vessels the lateral branches are inserted to ensure the blood supply of these vessels entering the aortic arch.

As mentioned above, the present invention also relates to an introduction system for introducing a self-expanding stent graft into a blood vessel of a patient, a stent graft like the one described above having to be introduced, featuring the system of introduction to compress and introduce the stent graft into the blood vessel further at least one pin member, which is configured to skewer and temporarily fix the handle-shaped fixation members that compress the stent graft, and which features a proximal and a distal end, and an intermediate zone located between the proximal and distal ends.

The pin element provided in the delivery system is also threaded through the handles, which, in each case, from their fixation point, were guided around the stent graft and thus compressed it. When threading the loops, they are fixed again, so the stent graft remains fully compressed. In this compressed form, the stent graft can be inserted into the blood vessel.

Accordingly, therefore, on release it is preferable that the stent graft compressed by retraction of the pin member in the proximal direction can be released and thereby release the handles which are held compressed by the stent graft.

In this document, with "proximal address" in this regard is indicated the direction from the user; Hereinafter, "pin element" will mean any elongated element in the form of a pin that is long enough and whose diameter is such that it can be threaded into at least some of the handles provided in the stent graft. Consequently, the pin element has a proximal end and a distal end and a proximal and a distal zone, as well as an intermediate zone located between these two ends / zones, the proximal end being as close as possible to the user or the person. that handles the introduction system. The pin elements are in this respect preferably stainless steel, but can be made of any other material suitable for the present purposes and provide sufficient or secure rigidity to hold the handles and therefore also the stent graft in place.

Therefore, when the pin element is retracted, the handles are released in stages again, so that they are no longer held together at the location opposite the fixation location on the perimeter of the stent, and the stent to this respect is no longer compressed and, as a consequence, is released.

According to another embodiment of the introduction system according to the invention, it has several pin elements of different lengths; these are configured and positioned by skewering the loop-shaped fasteners to compress and release the stent graft in such a way that different sections of the stent can be released by retracting the pin members of different lengths in a proximal direction.

Preferably, the pin elements are guided in this respect with their proximal end through a carrier element, with their movement in the proximal direction successively in the proximal direction of the pin elements due to their different lengths. In this way, the stent areas, which can advantageously be fixed / compressed by pin elements of different lengths, can be specifically released at different times.

If several pin elements of different lengths are provided for the delivery system according to the invention, it is preferable that the loop-shaped fastening elements are positioned offset against each other in each case on the rings of the endoprosthesis. In this embodiment, each pin element engages a pair of handle-shaped fasteners. If the loop-shaped fixation elements are positioned adjacently in each case on the rings in the longitudinal direction of the stent graft, it is preferable use a pin element; in this case, all pairs of handle-shaped fasteners are threaded by the single pin element.

According to another embodiment, in the introduction system according to the invention an additional catheter sheath is further provided which is arranged on the pin elements that compress the stent graft together with the loop-shaped fixation elements.

This embodiment achieves the ability to use both a catheter sheath and the latch / handle release mechanism to release the stent graft. This "combined" release mechanism is particularly advantageous in the case of stent grafts that have lateral branches or arms protruding from the main body of the stent graft: in this case, the entire stent graft can be released first generally by retracting the sheath of the stent. catheter, the stent graft site being held compressed with the arms by the pin element mechanism and handle-shaped fixation elements. In other words, in this way, the lateral branches / projecting arms can only be correctly positioned in the branching vessels, before this area is released by retraction of the pin element (s). In other words, in this case the pin element, in addition to being guided through the handles additionally, can also be guided through the arms.

In a preferred embodiment, it is further provided that the pin element is guided with its proximal end around a roller provided in a handle or housing of the introduction system.

This embodiment has the advantage that after retracting the catheter sheath, which preferably engages with the handle, and pulling it back to the proximal direction by the stent graft, the release path for the elements The pin length will be long enough to also guide the pins out of the handles and fully release the stent graft.

It is understood that the delivery system according to the present invention has apart from this also other features common to stent delivery systems, such as, for example, a pusher, catheter tube, etc .; For the person skilled in the art, it is recognizable from the teaching set forth herein what other characteristics and properties the introduction system may have to be functional for the corresponding application. For example, reference is made to EP 1964532.

Further advantages appear from the following description of advantageous embodiments and from the accompanying figures. It is understood that the characteristics mentioned above and those that will be explained below can be used not only in the combination indicated in each case, but also in other combinations or individually, without leaving the scope of the present invention.

The exemplary embodiments of the invention are represented in the following figures and are described in more detail in relation to them below. They show:

FIG. 1: a schematic sectional representation of a first embodiment of the endoprosthesis graft according to the invention;

FIG. 2: a schematic sectional representation of another embodiment of the endoprosthesis graft according to the invention;

Figure 3: an enlarged section of another embodiment of the stent graft according to the invention;

FIG. 4: a representation of the exemplary embodiment of the endoprosthesis graft according to the invention shown in FIG. 1, in compressed form with a threaded pin element;

Figure 5: a section of an embodiment of a stent graft according to the invention; Y

Figure 6: a schematic representation of an embodiment of the delivery system according to the invention of the endoprosthesis graft according to the invention.

In FIG. 1, at 10 there is generally shown a first embodiment of a stent graft according to the invention having a hollow cylindrical body 11 with a first stent graft section 12 with a self-expanding stent of rings arranged one behind the other. others in their longitudinal direction 14 from meander-shaped circular supports 15. The supports 15 are connected to each other on the outer side of the hollow cylindrical body 11 by means of a prosthetic material 17 fixed by seams 16 to the supports 15. The stent graft shown in Figure 1 further exhibits a second stent graft section 18; Unlike the first stent graft section 12, this second stent graft section 18 does not feature ring stents with meander-shaped circulating supports, but comprises only a second prosthetic material 19.

Furthermore, in FIG. 1 they are shown with 20, 21 handles or handle-shaped fastening elements, which are located in pairs on a support 15 of a ring 14 and there are placed in a common fastening zone 22; in the example shown in figure 1, the handle-shaped fastening elements 20, 21 are sewn to the supports 15 of a ring 14, namely, on a common support section 15, representing the fastening zone 22. The handles 20, 21 are in this respect equal or approximately equal in size.

In the figures, the same characteristics of the different embodiments are provided with the same reference numbers. The seams 16, through which the prosthetic material 17 is attached to the rings 14 of the stent, are not shown in Figures 2 to 5 for clarity.

Alternatively, in the embodiment shown in sections in figure 3, the common fixing area 22 'of the handle-shaped fixing elements 20, 21 is positioned in a point shape on the supports 15. In figure 3, They further show two arrows 26 and 27, indicating the direction in which the two handle-shaped fasteners 20, 21 are guided in each case to "integrate" or compress the hollow cylindrical body 11 of the stent graft 10.

Figure 2 shows another embodiment of the stent graft according to the invention: in this case, the second stent graft section 18 has lateral branches / arms 23, 24, 25, which are intended for insertion into protruding lateral vessels of the main vessel.

Figure 4 shows the embodiment of the endoprosthesis graft 10 according to the invention shown in Figure 1, namely in a partially compressed state: in this case, the handle-shaped fixation elements 20, 21, are have been guided in each case in different directions of flow around the hollow cylindrical body 11 of the stent graft 12 and then a pin element 26 has been threaded through the handles of the handle-shaped fixation elements 20, 21. As can be recognized in figure 4, the handles are found when guided in each case in opposite directions around the endoprosthesis graft, on the zones 28 opposite the fixation zones 22, 22 'on the perimeter of the endoprosthesis graft 10, where they are threaded through pin element 26.

Figure 5 shows another embodiment of the endoprosthesis graft according to the invention, in this case the first section of the endoprosthesis graft having 12 lateral arms or branches 40, 41, 42 and 43 provided for lateral vessels emerging from the main vessel.

The embodiment shown in Figure 5 may be intended, for example, for use in the abdominal aorta, so that the stent graft 10 with its hollow cylindrical body 11 is inserted into the abdominal aorta in such a way that the lateral branches 40, 41, 42 and 43, for example, can be located at the outlets of the celiac trunk, the superior mesenteric artery and the two renal arteries ( arteriae renales). In this embodiment, the pin element 26 can be guided through one of the arms 40, 41, 42, 43 and through the handle-shaped fixation elements 20, 21 that compress the stent graft 10.

Figure 6 schematically shows another embodiment of a delivery system according to the invention. The embodiment of the stent graft 10 according to the invention shown in FIG. 6 also has loop-shaped fixation elements 20, 21 which have been wound in each case in different directions around the stent graft 10. Furthermore, Several pin elements 27, 28, 29, 30 are provided, each threaded on a pair of handles 20, 21: thus, the pair of handles 20, 21 described with A is threaded through the pin element 27 , the pair of handles 20, 21 described with B, through the pin element 28, the pair of handles described with C, through the pin element 29, and the pair of handles described with D, through the pin 30.

The pin elements 27, 28, 29 and 30 are guided through their proximal end, that is, the end closest to the user, through a disk-shaped support element 32 that has four holes 34 through which the pin elements 27, 28, 29 and 30 are guided in each case. At the outermost end of the proximal zone of the pin elements 27, 28, 29 and 30, thickenings or elements of stop 36, the diameter of which is greater than the diameter of the holes 34.

In Figure 6, arrow 37 indicates the direction in which the pin members and the carrier member 32 are guided to release the stent graft 10 or individual stent graft zones successively: if the carrier member 32 moves in the proximal direction, i.e. from the user, pulls the pin elements 27, 28, 29, 30 through the stop of the stop / stop 36, namely, in the order in which the stop / stop elements 36 are "picked up" by the supporting element 32: in the example shown in figure 6, the pin element 30 is also first picked up and pulled in the proximal direction, therefore, in the embodiment shown in the Figure 6, zone D of stent graft 10 is first released and expanded; following movement in the proximal direction (see arrow 37) the pin element 27 is pulled, so that after removing the pin element 27 from the pair of handles 20, 21, the area A of the stent graft 10 can be expanded . Finally, there are still zones B and C, which can be expanded by dragging sequentially the stop elements 36 of the pin elements 28 and 29 and unthreading these pin elements 28, 29 from the pairs of handles 20, 21.

In this way, any area, depending on the arrangement and threading of the pin elements, can be released in a specific way at different times.

In another embodiment not shown, the pin element 26 or the pin elements 27, 28, 29, 30 are guided and wound on its proximal end (s) on a roller located in a handle or housing to handle the release / introduction system; this embodiment is particularly advantageous if, as described above, there is a catheter sheath (not shown in the figures) next to the delivery system according to the invention. This catheter sheath is arranged over the delivery system according to the invention of handle-shaped fixation elements 20, 21 and pin elements 26, 27, 28, 29, 30 and is consequently removed from the stent graft 10 before the delivery system according to the invention. Since the catheter sheath is often engaged with the handle / housing, and therefore the handle / housing is already guided in the proximal direction, usually only a short release path remains for the pin elements 26, 27, 28 , 29, 30, which would then also have to be pulled in a proximal direction. Winding or winding the pin elements 26, 27, 28, 29, 30 on the handle ensures that the release path is long enough to also remove the pin elements 26, 27, 28, 29, 30 or 27 , 28, 29, 30 of the loop-shaped fasteners 20, 21, thus completely releasing the stent graft 10.

Claims (10)

i. Stent graft (10) for introduction into a blood vessel of a patient, with a hollow cylindrical body (11) with a blood side and a vessel side, the stent graft (10) presenting the following: a first endoprosthesis graft section (12) with a self-expanding endoprosthesis of rings (14) arranged one behind the other in its longitudinal direction from circulating meander-shaped supports (15) and with a first prosthetic material (17) attached to the rings (14) and joining these to the cup side of the hollow cylindrical body (11); characterized in that the first endoprosthesis graft section (12) has in each of its rings (14) in each case two loop-shaped fixation elements (20, 21) placed on a common fixation zone (22), placed on the supports (15) of the rings (14) in such a way that by means of their guide located in an opposite way around the hollow cylindrical body (11) they can be compressed around it along its entire length. Stent graft (10) according to claim 1, characterized in that the fixation elements (20, 21) are displaced on the perimeter of the hollow cylindrical body (11) of the stent graft (10) or positioned adjacently one behind others on the supports (15). Stent graft (10) according to one of the preceding claims, characterized in that the first stent graft section (12) furthermore has at least one lateral stent branch (40, 41, 42, 43) configured to be inserted into a vessel that branches off the blood vessel. Stent graft (10) according to one of the preceding claims, characterized in that it has a second stent graft section (18), with a tubular body of a second prosthetic material (19), in which the second section of stent graft (18) has no stent ring. 5. Stent graft (10) according to claim 4, characterized in that the second stent graft section (18) has at least one side branch of stent (23, 24, 25). Delivery system for introducing a self-expanding stent graft (10) into a blood vessel of a patient, characterized in that the delivery system has a stent graft (10) according to one of claims 1 to 5, and to compressing and introducing the stent graft (10) into the blood vessel, at least one pin member (26; 27; 28; 29; 30), which is configured to pick up in a skewered manner and temporarily fix the fasteners in a handles (20, 21) that compress the stent graft (10), the pin element (26; 27; 28; 29; 30) having a proximal end and a distal end, as well as an intermediate section between them. Introduction system according to claim 6, characterized in that the compressed stent graft (10) can be released by retraction of the pin element (26; 27; 28; 29; 30) in the proximal direction and thus releasing the handle-shaped fasteners (20, 21) that are held compressed by the stent graft (10). 8. Delivery system according to claim 6 or 7, characterized in that several pin elements (26; 27; 28; 29; 30) are provided with different lengths to release different sections of the stent graft. Introduction system according to one of claims 6 to 8, characterized in that a catheter sheath is additionally provided which is arranged on the stent graft (10) in conjunction with the pin elements (26; 27; 28; 29; 30) that compress the handle-shaped fasteners (20, 21). Insertion system according to one of Claims 6 to 9, characterized in that it furthermore has a handle as well as a roller on the handle on which the pin element (26; 27; 28; 29; 30) can be guided with its proximal end.